Device for 3D printing and control method thereof

ABSTRACT

A device for 3D printing and a control method thereof are provided. The device includes: a feeding pipe, where an opening extending along an axial direction of the feeding pipe is disposed on an outer wall of the feeding pipe; and a sleeve sleeved on the feeding pipe, where a discharge port in communication with the opening is disposed on an outer wall of the sleeve. Compared with a conventional design, the above device utilizes a sleeve to provide a discharge port and sleeves the sleeve and the feeding pipe together, thereby making the structure of the entire device more compact.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2018/113069, filed on Oct. 31, 2018, the disclosure of which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present application relates to a field of 3D printing, moreparticularly, to a device for 3D printing and a control method thereof.

BACKGROUND

Fused deposition modeling (FDM) technology is a common 3D printingtechnology. The FDM technology generally involves heating material to afused state (or a semi-flow state), and extruding the fused materialfrom a discharge port (or an extrusion port) of a 3D printing head, andthe material is deposited layer by layer on a printing platform to forma 3D article.

A conventional 3D printing head has a feeding portion and a nozzle forforming a discharge port. The nozzle is typically mounted at the lowerend of the feeding portion, resulting in a less compact structure of adevice.

SUMMARY

The present application provides a device for 3D printing and a controlmethod thereof, which can make the structure of the device more compact.

In a first aspect, provided is a device for 3D printing, including: afeeding pipe, where an opening extending along an axial direction of thefeeding pipe is disposed on an outer wall of the feeding pipe; and asleeve sleeved on the feeding pipe, where a discharge port incommunication with the opening is disposed on an outer wall of thesleeve.

In a second aspect, provided is a control method of a device for 3Dprinting, where the device for 3D printing includes: a feeding pipe,where an opening extending along an axial direction of the feeding pipeis disposed on an outer wall of the feeding pipe; and a sleeve sleevedon the feeding pipe, where a discharge port in communication with theopening is disposed on an outer wall of the sleeve; and the controlmethod includes: adjusting a size of the discharge port.

In a third aspect, provided is a computer readable storage medium havingstored thereon instructions for performing the control method of thesecond aspect.

In a fourth aspect, provided is a computer program product includinginstructions for performing the control method of the second aspect.

In contrast to the conventional design (a nozzle is disposed at thebottom of a feeding portion), the present application utilizes a sleeveto provide a discharge port, by assembling sleeve the sleeve and thefeeding pipe together, making the overall structure of a device morecompact.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an overall structure of a conventional3D printing device;

FIG. 2 is a schematic diagram of a structure of a conventional 3Dprinting head;

FIG. 3a is an exemplary diagram of a printing region of a layer to beprinted;

FIG. 3b is an exemplary diagram of an arrangement manner of passes;

FIG. 4 is an exemplary diagram of a structure of a device for 3Dprinting provided by an embodiment of the present application;

FIG. 5 is an exemplary diagram of a three dimensional structure of afeeding pipe provided by an embodiment of the present application;

FIG. 6 is a two-dimensional plan view of the feeding pipe shown in FIG.5;

FIG. 7 is a structural view of the device shown in FIG. 4 after supportsare removed;

FIG. 8 is an exemplary diagram of a three dimensional structure of aseparable portion of a separable sleeve provided by an embodiment of thepresent application;

FIG. 9 is a two-dimensional plan view of the separable portion shown inFIG. 8;

FIG. 10 is a schematic diagram of a manner in which the separableportion shown in FIG. 8 and a feeding pipe are assembled;

FIG. 11 is an exploded view of various separable portions of a separablesleeve provided by an embodiment of the present application;

FIG. 12 is an assembled view of the various separable portions shown inFIG. 11;

FIG. 13 is an exploded view of various separable portions of a separablesleeve provided by another embodiment of the present application;

FIG. 14 is an assembled view of the separable sleeve shown in FIG. 13and a feeding pipe;

FIG. 15 is an exemplary diagram of a separable sleeve with a closed ringdesign at ends provided by the embodiment of the present application;

FIG. 16 is an exemplary diagram of a three dimensional structure of aseparable portion of a separable sleeve provided by another embodimentof the present application;

FIG. 17 is an assembled view of a sleeve spliced from the separableportion shown in FIG. 16 and a feeding pipe;

FIG. 18 is an exemplary diagram of a printing process of a deviceprovided by an embodiment of the present application;

FIG. 19 is a comparison diagram of printing effects of a device providedby an embodiment of the present application and a conventional 3Dprinting method;

FIG. 20 is an exemplary diagram of a pass switching manner in aconventional 3D printing method;

FIG. 21 is an exemplary diagram of a feeding apparatus provided by anembodiment of the present application; and

FIG. 22 is a schematic flowchart of a control method provided by anembodiment of the present application.

DESCRIPTION OF EMBODIMENTS

For ease of understanding, a brief introduction to a conventional 3Dprinting device is first provided.

As shown in FIG. 1, a conventional 3D printing device 1 may generallyinclude a feeding apparatus 11, a 3D printing head 12, a printingplatform 13 and a control apparatus 14 (the above structure divisionmanner is merely an example, and in fact, other structural divisionmanners may also be adopted. For example, the control apparatus and/orthe feeding apparatus 11 may belong to a part of the 3D printing head12).

The feeding apparatus 11 may be connected to a scroll 15. In an actualprinting process, the feeding apparatus 11 may take a filamentousmaterial from the scroll 15, and convey the filamentous material to the3D printing head 12. Material used in a 3D printing process is generallya thermoplastic material, such as a high-molecular polymer, alow-melting-point metal, or other materials that can be formulated asflowable pastes (such as paste-like cream, high-melting-point metalpowder mixtures, cement or the like).

As shown in FIG. 2, the 3D printing head 12 may generally include afeeding portion 121, a nozzle 122 and a temperature control apparatus123. The temperature control apparatus 123 is generally disposed outsidethe feeding portion 121 and configured to heat material conveyed by thefeeding apparatus 11 to the feeding portion 121 to a molten state. Thetemperature control apparatus 123 may be, for example, a heatingapparatus. The nozzle 122 is mounted at the lower end of the feedingportion 121. The nozzle may provide a discharge port 124, and thus mayextrude the material in a molten state conveyed by the feeding portion121 onto the printing platform 13.

The control apparatus 14 may be configured to control the 3D printinghead 12 to print an article layer by layer. During a process of printingeach layer, the 3D printing head 12 may be controlled to completelyprint all of a printing region of a layer to be printed (that is, thewhole region enclosed by a cross-sectional contour line of the layer tobe printed) according to a preset printing path.

An overall process of conventional 3D printing is generally as follows.

Before an article is printed, a 3D model of the article may be createdby using modeling software. The modeling software may be, for example,computer aided design (CAD) software. Then, a layer processing isperformed on the created 3D model, so as to divide the 3D model intomultiple layers to be printed and obtain layer data of each layer to beprinted. The layer processing of a 3D model is considered as decomposinga 3D article printing process into many 2D printing processes, and theprinting process of each layer to be printed is similar to a planar 2Dprinting process. After obtaining the layer data of each layer to beprinted, the control apparatus 14 may control the 3D printing head 12 tomove along a certain filling path according to the layer data of eachlayer to be printed, and in a process of movement, the material in amolten state is extruded onto the printing platform 13 through thedischarge port 124 to print or fill a printing region of each layer tobe printed. After all layers to be printed of the article are printed,the material is solidified layer by layer to form a 3D article.

For ease of understanding, a printing process of a certain layer to beprinted by the conventional 3D printing device will be described indetail below by taking FIG. 3a and FIG. 3b as examples.

Referring to FIG. 3a and FIG. 3b , a printing region of a layer to beprinted is region 31, and a cross-sectional contour line of the region31 is cross-sectional contour line 32.

In order to completely print the region 31, the region 31 is generallydivided into a plurality of closely arranged passes based on thecross-sectional contour line 32, such as pass A₁ to pass A₂₅ shown inFIG. 3 b.

In a process of printing, the control apparatus 14 controls az-coordinate of the 3D printing head 12 to be unchanged, and controlsthe 3D printing head 12 to completely print all passes in a certainorder, for example, printing the passes A₁-A₂₅ in sequence along astraight path in a parallel reciprocation manner.

For example, in a case of a printing process of pass A₁, the controlapparatus 14 may first move the 3D printing head 12 to a position aboveposition point p1 shown in FIG. 3a , and then control the 3D printinghead 12 to move from the position above the position point p1 to aposition above position point p2. During a movement process, material ina molten state is extruded onto the pass A₁ through the discharge port124, so as to print the pass A₁. A printing manner of other passes issimilar, and will not be described redundantly herein. After all thepasses are printed, a printing process of the layer to be printed iscompleted, and the 3D printing head 12 or the work platform 13 may becontrolled to move along the z-axis direction to prepare printing of anext layer.

As previously described, the conventional 3D printing head 12 has afeeding portion 121 and a nozzle 122 for providing a discharge port 124.The nozzle 122 is typically mounted at the lower end of the feedingportion 121, resulting in a less compact structure of the 3D printinghead 12.

A device for 3D printing provided by an embodiment of the presentapplication will be described in detail below. It should be noted thatthe device for 3D printing may refer to a 3D printing head, and may alsorefer to an entire 3D printer or a 3D printing system.

As shown in FIG. 4, a device 4 for 3D printing may include a feedingpipe 5 and a sleeve 6. The sleeve 6 may be sleeved on the feeding pipe 5to form a sleeve joint assembly that is compact in structure.

Referring to FIG. 5 to FIG. 6, an opening 52 is disposed on an outerwall of the feeding pipe 5 (the opening 52 may extend, for example,along an axial direction of the feeding pipe 5).

In some embodiments, the feeding pipe 5 may belong to one of the entirefeeding portion of the device 4. In addition to the feeding pipe 5, thefeeding portion may also include other portions in communication withthe feeding pipe 5.

In other embodiments, the feeding pipe 5 is a feeding portion of thedevice 4, and a feed port 54 may be disposed on an end surface of thefeeding pipe 5 or on the outer wall of the feeding pipe 5.

An interior of the feeding pipe 5 (hereinafter referred to as a feedingpassage) may be of an arc design. For example, referring to FIG. 5 toFIG. 6, the feeding passage may be designed as a cylindrical passage.Moreover, in some embodiments, an arc transition is also adopted betweenthe cylindrical passage and its ends. The feeding passage adopts an arcdesign, which not only enables a molten material to be smoothly conveyedin the feeding passage, but also facilitates the cleaning of the feedingpassage, and avoids material waste due to retention in the interior ofthe feeding passage as much as possible.

The sleeve 6 may be sleeved on the feeding pipe 5, that is, the feedingpipe 5 may be seen as an inner pipe of the sleeve 6. In someembodiments, the sleeve 6 may be a one-piece sleeve, such as anintegrally formed sleeve. In other embodiments, the sleeve 6 may be aseparate sleeve, that is, an outer wall of the sleeve 6 may include aplurality of separable portions, or an outer wall of the sleeve 6 may bespliced from a plurality of separable portions.

As shown in FIGS. 7-9, the outer wall of the sleeve 6 may include afirst portion 61 and a second portion 62 that are separable. The firstportion 61 may be assembled with the feeding pipe 5 in the manner shownin FIG. 10. The second portion 62 may have a complementary structure tothe first portion 61, and the two are spliced together in the mannershown in FIG. 7 to form the outer wall of the sleeve 6.

In some embodiments, the outer wall of the sleeve 6 may also beassembled from three or more separable portions. For example, in FIGS.11 to 12, the outer wall of the sleeve 6 includes a first portion 61, asecond portion 62, a third portion 63 and a fourth portion 64 that areseparable, edges of which are spliced to each other to form the outerwall of the sleeve 6.

The sleeve 6 may be fixed to the feeding pipe 5 or movable relative tothe feeding pipe 5. For example, the sleeve 6 may move along an axialdirection of the feeding pipe 5; for another example, the sleeve 6 mayrotate around an axis of the feeding pipe 5; and for yet anotherexample, the sleeve 6 may not only move along an axial direction of thefeeding pipe 5, but also rotate around an axis of the feeding pipe 5.

A discharge port 65 that may be in communication with the opening 52 isdisposed on the outer wall of the sleeve 6. In some embodiments, similarto the opening 52, the discharge port 65 may also extend along the axialdirection of the feeding pipe 5, that is, a length direction of thedischarge port 65 may be the axial direction of the feeding pipe 5.

The discharge port 65 may always be in communication with the opening52. For example, the discharge port 65 may be fixed below the opening52. Alternatively, in some embodiments, the sleeve 6 may be movablerelative to the feeding pipe 5 such that the discharge port 65 may movebelow the opening 52 to be in communication with the opening 52.

The discharge port 65 may be a discharge port with a fixed size or adischarge port with an adjustable size. The adjustable size of thedischarge port 65 may refer that a length of the discharge port 65 isadjustable (or the length is continuously adjustable), or a width of thedischarge port 65 is adjustable (or the width is continuously adjusted),or both length and width of the discharge port 65 are adjustable (orcontinuously adjustable).

The discharge port 65 may be designed as a discharge port with anadjustable size in a variety of manners. Several possible implementationmanners are given below.

For example, as one possible implementation manner, one or more shuttersmay be provided at the discharge port 65 to adjust the size of thedischarge port 65.

For another example, as another possible implementation manner, thesleeve 6 may include a plurality of separable portions. Abutting facesof the plurality of portions may form a plurality of discharge ports,and the plurality of portions may be movable relative to each other(e.g., moveable along the axial direction of the feeding pipe 5) toadjust the size of the discharge port 65.

For example, in FIG. 7, the sleeve 6 may include a first portion 61 anda second portion 62. The first portion 61 and the second portion 62 areslidable relative to each other along the axial direction of the feedingpipe 5 so as to form the discharge port 65 with an adjustable (orcontinuously adjustable) length.

Shapes of the first portion 61 and the second portion 62 and manners inwhich they form the discharge port 65 may be various.

As an example, as shown in FIG. 7, the first portion 61 may include afirst upper stepped surface 611, a first lower stepped surface 612 and afirst connecting surface 613 connecting the first upper stepped surface611 and the first lower stepped surface 612. The second portion 62 mayinclude a second upper stepped surface 621, a second lower steppedsurface 622 and a second connecting surface 623 connecting the secondupper stepped surface 621 and the second lower stepped surface 622. Thefirst upper stepped surface 611 is in contact with the second lowerstepped surface 622, and the two are slidable relative to each otheralong the axial direction of the feeding pipe 5 (in other words, thefirst upper stepped surface 611 and the second lower stepped surface 622are in slidable connection along the axial direction of the feeding pipe5). The first lower stepped surface 612 is in contact with the secondupper stepped surface 621, and the two are slidable relative to eachother along the axial direction of the feeding pipe 5 (in other words,the first lower stepped surface 612 and the second upper stepped surface621 are in slidable connection along the axial direction of the feedingpipe 5). A hollow area formed by the first lower stepped surface 612,the first connecting surface 613, the second lower stepped surface 622and the second connecting surface 623 may thus serve as the dischargeport 65.

In this example, the first portion 61 and the second portion 62 areabutted together using a staggered complementary stepped structure, andthe two are slidable relative to each other along the axial direction ofthe feeding pipe 5 to form the discharge port 65 with a continuouslyadjustable length. The width of the discharge port 65 depends on adifference in height between the first upper stepped surface 611 and thefirst lower stepped surface 612 (or the second upper stepped surface 621and the second lower stepped surface 622). The implementation manner ofsuch a discharge port can form a discharge port 65 having a small widthon the premise of ensuring the size and strength of the first portion 61and the second portion 62 (the width of the discharge port can affectprinting accuracy).

As another example, the first portion 61 and the second portion 62 mayhave a concave-convex complementary structure. The relative sliding ofthe first portion 61 and the second portion 62 along the axial directionof the feeding pipe 5 may change a relative positional relationshipbetween concave-convex portions, and a hollow area between theconcave-convex portions may thus form the discharge port 65.

The above indicates that the first portion 61 and the second portion 62are slidable relative to each other along the axial direction of thefeeding pipe 5. It should be noted that not both the first portion 61and the second portion 62 are required to be slidable relative to thefeeding pipe 5 in the embodiment of the present application.

As one possible implementation manner, both the first portion 61 and thesecond portion 62 are slidable relative to the feeding pipe 5.

As another possible implementation manner, as shown in FIGS. 13 to 14,the first portion 61 is slidable relative to the feeding pipe 5, and thesecond portion 62 is fixedly connected to the feeding pipe 5 orintegrally formed with the feeding pipe 5. This implementation mannercan simplify the control of the device 4.

As shown in FIG. 7 or FIG. 15, in some embodiments, an end 614 of thefirst portion 61 may be designed as a closed ring sleeved on the feedingpipe 5; and/or an end 624 of the second portion 62 (the end 614 and theend 624 may define a length of the sleeve 6 along the axial direction)may be designed as a closed ring sleeved on the feeding pipe 5. Thiscould enhance the overall rigidity and tightness of the sleeve 6.

In some embodiments, when the first portion 61 is a sliding part and thesecond portion 62 is a fixing part, as shown in FIGS. 13 to 14, two endsof the first portion 61 may be designed as closed rings. This couldenhance the overall rigidity and tightness of the sleeve 6.

The relationship between the size of the discharge port 65 and the sizeof the opening 52 is not specifically limited in the embodiment of thepresent application. The size of the discharge port 65 may be the sameas or different from the size of the opening 52.

For example, the length of the discharge port 65 (when the dischargeport 65 is a discharge port with an adjustable length, the length of thedischarge port 65 may refer to the maximum length of the discharge port65) may be less than the length of the opening 52; for another example,the width of the discharge port 65 (when the discharge port 65 is adischarge port with an adjustable width, the width of the discharge port65 may refer to the maximum width of the discharge port 65) may be lessthan the width of the opening 52.

The adjustment of the size of the discharge port 65 may be achieved bymeans of a drive apparatus. For example, in FIG. 4, a support 91 forfixing the first portion 61 and a support 92 for fixing the secondportion 62 may be disposed on the sleeve 6. A drive apparatus 7 mayprovide the support 91 and the support 92 with power of movement alongthe axial direction of the feeding pipe 5, so that the first portion 61is driven to move along the axial direction by the support 91, and thesecond portion 62 is driven to move along the axial direction by thesupport 92.

The drive apparatus 7 may be specifically implemented in a variety ofmanners, which is not limited in the embodiment of the presentapplication, and may be, for example, a rack and pinion mechanism or acrank slider mechanism.

The outer wall of the sleeve 6 may be provided with one discharge port65, or may be provided with a plurality of discharge ports 65. Forexample, the outer wall of the sleeve 6 may be provided with twodischarge ports, three discharge ports, four discharge ports, and eightdischarge ports. The sleeve 6 is movable relative to the feeding pipe 5such that the opening 52 is capable of being in communication withdifferent discharge ports 65 (that is, realizing a switch between thedifferent discharge ports 65).

As an example, the plurality of discharge ports 65 may be arranged alongthe axial direction of the feeding pipe 5. In this case, the sleeve 6may be translated along the axial direction of the feeding pipe 5 suchthat the opening 52 is capable of being in communication with differentdischarge ports 65.

As another example, the plurality of discharge ports 65 may be arrangedalong a circumferential direction of the sleeve 6. In this case, thesleeve 6 is rotatable around an axis of the feeding pipe 5 such that theopening 52 is capable of being in communication with different dischargeports 65. In order to achieve rotation of the sleeve 6 around the axisof the feeding pipe 5, the device 4 may also be designed with acorresponding drive apparatus. The drive apparatus may be, for example,a gear transmission mechanism.

Of course, a combination of the above two examples is also possible.

Hereinafter, with reference to FIGS. 11, 12, 16 and 17, exemplarydescription is made to a manner in which a plurality of discharge ports65 are formed on an outer wall of a sleeve 6 in detail.

As one possible implementation manner, referring to FIGS. 16 to 17, thesleeve 6 may include a first portion 61 and a second portion 62. Thefirst portion 61 and the second portion 62 are similar to the firstportion 61 and the second portion 62 shown in FIGS. 7 and 8, except thatin FIGS. 16 to 17, two abutting faces of the first portion 61 and thesecond portion 62 are both stepped abutting faces, and specifically,stepped abutting faces 611 a, 612 a and 613 a of the first portion 61and the corresponding faces of the second portion are used to form adischarge port 65 a; and stepped abutting face 611 b, 612 b and 613 b ofthe first portion 61 and the corresponding faces of the second portionare used to form a discharge port 65 b.

As another possible implementation manner, referring to FIG. 11 to FIG.12, the sleeve 6 is formed by splicing four portions 61, 62, 63, 64, andeach two adjacent portions form a discharge port, and a total of fourdischarge ports 65 a, 65 b, 65 c, 65 d are formed. Of course, in someembodiments, abutting faces of two adjacent portions may also bedesigned as a plane, so that a discharge port will not be formed betweenthe two adjacent portions, and furthermore, any number of dischargeports can be designed according to actual needs (for example, an oddnumber of discharge ports can be designed, or an even number ofdischarge ports can be designed).

Sizes of a plurality of discharge ports 65 are not specifically limitedin the embodiment of the present application. The plurality of dischargeports 65 may be discharge ports of the same size (if the discharge ports65 are discharge ports with adjustable sizes, the same size may referthat the maximum sizes of the discharge ports 65 are the same), ordischarge ports of different sizes.

As an example, lengths (or maximum lengths) of the plurality ofdischarge ports 65 are different.

As another example, widths of the plurality of discharge ports 65 aredifferent. The widths of the discharge ports 65 affect a width of anextruded material, which in turn affects accuracy of 3D printing. Theplurality of discharge ports 65 with different widths are designed sothat the device 4 can select the discharge ports with different levelsof accuracy for printing according to actual needs.

For example, assuming that a layer to be printed includes a firstprinting region in which a cross-sectional contour line changes sharplyin a vertical direction and a second printing region in which across-sectional contour line changes gently in the vertical direction,when the device 4 is used to print the first printing region, it can beswitched to a discharge port with a smaller width, thereby improvingprinting accuracy; and when the device 4 is used to print the secondprinting region, it can be switched to a discharge port with a largerwidth, thereby improving printing efficiency on the premise of printingaccuracy.

Of course, the combination of the above cases is also possible, that is,widths and lengths (or the maximum lengths) of the plurality ofdischarge ports 65 are all different.

As indicated above, the discharge port 65 provided by the embodiment ofthe present application may be a discharge port 65 with a continuouslyadjustable length. Compared with design of a discharge port of aconventional 3D printing head, the discharge port 65 is designed as adischarge port with the continuously adjustable length, which overcomesthe limitation of the conventional discharge port design concept, andhas obvious advantages and broad application prospects. The following isan analysis of this.

A discharge port of a conventional 3D printing head is generallydesigned as a nozzle in a fixed shape. A common shape of the nozzleincludes a round hole, a square hole, or a slightly deformed irregularshaped hole with equal diameter. A diameter of the nozzle is generallyabout 1 mm, and a common diameter is 0.4 mm. When an article is requiredto be high in printing accuracy, a nozzle with a small diameter isgenerally selected. Such type of nozzle has less the amount of thematerial extrusion per unit time and is lower in printing efficiency.When an article is required to be high in printing efficiency, a nozzlewith a large diameter is generally selected. Such type of nozzle printsan article in a rough shape and is lower in printing accuracy. Thus itcan be seen that the conventional 3D printing head cannot take bothprinting efficiency and printing accuracy of 3D printing into account. Aformation process of such design manner of a conventional discharge portis analyzed below.

A 3D printing technology is a more advanced manufacturing technologydeveloped on the basis of a 2D printing technology. Generally, before 3Dprinting, it usually needs to perform layer processing on a 3D model ofan article to be printed. The layer processing is equivalent todecomposing a 3D article printing process into many 2D printingprocesses, that is, a printing process of each layer may be consideredas a planar printing process. Therefore, a conventional 3D printingdevice follows many design concepts of a 2D printing device. Mostobviously, a discharge port of a 2D printing head generally adopts anozzle in a fixed shape. A discharge port of a 3D printing head,following the design manner of the discharge port of the 2D printinghead, is also designed as a nozzle in a fixed shape. As mentioned above,the design of such type of nozzle results in that 3D printing headcannot take both printing efficiency and printing accuracy into account,and becomes a key obstacle to the development of the 3D printingtechnology.

A discharge port 65 in an embodiment of the present application isdesigned as a discharge port with a continuously adjustable lengthwithin a certain range. This is a design based on a full considerationof characteristics of a 3D printing object. Compared with theconventional 3D printing device, a 3D printing device provided by anembodiment of the present application makes it possible to take bothefficiency and accuracy of 3D printing into account, and is moresuitable for 3D printing. Specific illustration is as follows.

A 2D printing object is generally small in size, and the printing objectis mainly a text or an image. The text or image may be freely arrangedin a two dimensional plane and there is no rule to follow. Therefore, itis common to design a discharge port of a 2D printing device as a nozzlein a fixed shape, and such design is reasonable in the field of 2Dprinting. Different from the 2D printing object, a 3D printing object isgenerally a 3D article for practical usage. Since the 3D article has acertain physical contour, an intercept line of the 3D article along onesection is generally one or more closed and continuously changingcurves. Making full use of such characteristic of the 3D printingobject, the embodiment of the present application designs a dischargeport 65 as a discharge port with a continuously adjustable length. Thecontinuous adjustment of the length of the discharge port 65 coincideswith the characteristic that a cross-sectional contour line of the 3Dprinting object is closed and continuously changing. Such discharge port65 is more suitable for 3D printing, making it possible to greatlyincrease the printing efficiency.

For example, with a discharge port provided by the embodiment of thepresent application, continuous printing may be performed along across-sectional contour line. During printing, the discharge port 65 iscontrolled to change according to changes of the cross-sectional contourline. It should be understood that compared to a manner of conventionalprinting on a pass-by-pass basis, printing along the cross-sectionalcontour line has ultrahigh printing efficiency.

Further, a width of the discharge port 65 may be set as a fixed smallvalue, enabling printing accuracy of a 3D article to maintain unchangedand at a higher accuracy. The printing accuracy is maintained unchangedduring continuous change of the discharge port 65, which is difficult tobe realized by a conventional 3D printing head. Therefore, a dischargeport with a continuously adjustable length provided by an embodiment ofthe present application makes it possible to take both printingefficiency and printing accuracy of 3D printing into account, and ismore suitable for the 3D printing.

Hereinafter, with reference to specific embodiments, exemplarydescription is made to a changing manner of the length of the dischargeport 65 in detail.

Optionally, the length of the discharge port 65 may be controlled tocontinuously change according to a shape of a target printing region (orthe length of the discharge port 65 may be controlled to change with achange of the shape of the target printing region), and the targetprinting region may be part of a printing region of a layer to beprinted or all of the printing region of the layer to be printed.

For example, in some embodiments, the size of the discharge port 65 maybe adjusted such that the length of the discharge port 65 matcheslengths of intercept line segments of a cross-sectional contour line ofa target printing region of a layer to be printed.

For another example, in some embodiments, the size of the discharge port65 may be adjusted such that two ends of the discharge port 65 arealigned with the cross-sectional contour line of the target printingregion in a vertical direction.

When the two ends of the discharge port 65 are aligned with thecross-sectional contour line of the target printing region in thevertical direction, projection of the two ends of the discharge port 65in the vertical direction will fall on the intercept line segments ofthe cross-sectional contour line of the target printing region. Forconvenience of description, this printing method will hereinafter bereferred to as tracking printing of the cross-sectional contour line ofthe target printing region.

The tracking printing will be described in more detail below withreference to FIG. 18.

Referring to FIG. 18, reference sign 100 denotes a target printingregion of a layer to be printed, and a length of the discharge port 65extends along an x direction. During printing of the target printingregion 100, the device 4 may be controlled to move generally towards a ydirection. During the movement of the device 4, the length and/orposition of the discharge port 65 are changed in real time such that twoends of the discharge port 65 are always aligned with a cross-sectionalcontour line of the target printing region 100 in a vertical direction z(perpendicular to an x-y plane), that is, projection of the two ends ofthe discharge port 65 in the vertical direction z always falls on thecross-sectional contour line of the target printing region 100.

For example, assuming that y coordinate of the current position of thedischarge port 65 is y1, and the cross-sectional contour line of thetarget printing region 100 is transected at y1 along the x direction toobtain two points (x1, y1) and (x2, y1), positions of two ends of thedischarge port 65 can be changed such that the first end is locateddirectly above (x1, y1) and the second end is located directly above(x2, y1), and further, accurate tracking printing can be performed onthe cross-sectional contour line of the target printing region 100.

The tracking printing of the cross-sectional contour line of the targetprinting region may be implemented in a variety of manners. Optionally,as a first implementation manner, the positions of two ends of thedischarge port 65 may be adjusted such that the two ends of thedischarge port 65 are aligned with the cross-sectional contour line ofthe target printing region in the vertical direction.

Optionally, as a second implementation manner, the size of the dischargeport 65 may be adjusted such that the length of the discharge port 65matches the lengths of the intercept line segments of thecross-sectional contour line of the target printing region of the layerto be printed; and a relative position between the feeding pipe 5 andthe sleeve 6 as a whole and the printing platform is adjusted by using adrive apparatus such that two ends of the discharge port 65 are alignedwith the cross-sectional contour line of the target printing region in avertical direction.

In the process of printing the target printing region, the device 4 mayimplement tracking printing by using one of the above two implementationmanners according to actual needs; or, different tracking printingmethods may also be used when different parts of the target printingregion are printed.

For example, the target printing region may include a portion having ashorter length of the intercept line segment and a portion having alonger length of the intercept line segment. When a portion with a shortlength of the intercept line segment is printed, the firstimplementation manner may be used for tracking printing to simplify thecontrol of the device 4; and when a portion with a longer length of theintercept line segment is printed, the second implementation manner maybe used for tracking printing.

Compared with an article printed by a conventional discharge port, across-sectional contour line of a target printing region is tracked andprinted, and the printed article also has a significant improvement inmechanical properties and shape uniformity. Referring to FIG. 19 andFIG. 20, detailed illustration is given thereto.

Conventional 3D printing is generally performed on a pass-by-pass basisaccording to a certain pass sequence. Since a size of a discharge portof a conventional 3D printing device is small (a diameter is generallyof a millimeter level), it takes a long time to print each pass. When acurrent pass is prepared to be printed, material on a previous passadjacent to the current pass may have been in or close to asolidification state, and material on the current pass is still in amolten state. The material in the molten state on the current pass needsto be fused with the material on the previous pass that have been in orclose to a solidification state to form an integral part. A process ofmaterial fusion between adjacent passes herein is called a pass overlap.

In a process of a pass overlap, if the previous pass of the current passhas already solidified or been close to solidified and the current passis still in a molten state, a phenomenon of poor fusion may occur in amaterial fusion process between adjacent passes, which results in a poormechanical property of a printed article. In addition, since the stateof materials is not synchronized, a shape of an object obtained afterfusion of materials on adjacent passes is also relatively rough. Forexample, in a case of printing a cylinder, as shown in FIG. 19, acylinder 101 is printed in a pass overlap manner by using a conventional3D printing technique. The cylinder 101 not only has an overall roughshape and contour, but also has a plurality of notches 103 due to poormaterial fusion in a process of pass overlap.

A device 4 provided by an embodiment of the present application tracksand prints a cross-sectional contour line of a target printing region byadjusting a length and a position of a discharge port 65. Therefore, inthe process of printing the target printing region, the device 4 doesnot need to perform printing on a pass-by-pass basis according to apass, so that it is not necessary to perform a pass overlap, and noproblem of poor fusion occurs. Therefore, an article printed by thedevice 4 has a high mechanical property. As shown in FIG. 19, a cylinder102 is printed by a device 4. Compared to the cylinder 101, a fillingmaterial of the cylinder 102 is in good fusion condition, and there isno problem of poor fusion caused by a pass overlap.

To still take the case of printing a cylinder as an example, referringto FIG. 20, in a conventional 3D printing process, a switch betweenpasses is performed according to a fold line 104 instead of a realcontour curve, that is, a fold line is used to approximate a realcontour curve, resulting in that a printed contour line of a cylinder101 is relatively rough. A device 4 provided by an embodiment of thepresent application does not need to perform printing according to apass, but tracks and prints a cross-sectional contour line of a targetprinting region by adjusting a length and a position of a discharge port65. Therefore, a contour line of a cylinder 102 printed by the device 4is also smoother and more realistic.

The target printing region may be determined in a variety of manners.For example, whether all of the printing region of a layer to be printedis regarded as a target printing region or divided into a plurality oftarget printing regions respectively for printing may be determinedaccording to one or more factors of a shape of a cross-sectional contourline of the layer to be printed, a length of the longest intercept linesegment, and a size of a discharge port.

For example, when a length of the longest intercept line segment of thecross-sectional contour line of the layer to be printed is less than orequal to the maximum length of the discharge port, all of the printingregion of the layer to be printed may be determined as the targetprinting region; or when a length of the longest intercept line segmentof the cross-sectional contour line of the layer to be printed isgreater than the maximum length of the discharge port, all of theprinting region of the layer to be printed is divided into a pluralityof the target printing regions.

As another example, when the cross-sectional contour line of the layerto be printed encompasses a plurality of closed regions that are not incommunication, each of the closed regions may be regarded as one or moretarget printing regions for printing.

As another example, in some embodiments, instead of dividing all of aprinting region of the layer to be printed, all of the printing regionof the layer to be printed is directly regarded as the target printingregion. For example, the device 4 may be designed as a special-purposedevice that specifically prints a particular article, and the length ofthe discharge port 65 of the device 4 is designed to be able to printall of the printing region of each printing layer of the article atonce. In this way, in actual operation, the device 4 can print eachlayer of the article in a fixed manner without the need to divide theprinting region online.

As shown in FIG. 21, the device 4 may further include a feedingapparatus 200. The feeding apparatus 200 may feed material for thedischarge port 65 through the feeding pipe 5. The device 4 may furtherinclude a drive apparatus (not shown in the figure) configured to drivethe feeding apparatus 200. Driving of the feeding apparatus by the driveapparatus can enable the amount of the material extrusion of thedischarge port 65 to match the size of the discharge port.

The feeding apparatus 200 may be a screw feeding apparatus as shown inFIG. 21 (a), a pneumatic feeding apparatus as shown in FIG. 21 (b) or apiston feeding apparatus as shown in FIG. 21 (c).

In the case that the feeding apparatus 200 is a screw feeding apparatus,an amount of material extruded from a discharge port 65 may becontrolled in such a way that a drive apparatus adjusts a rotation speedof a screw; in the case that the feeding apparatus 200 is a pneumaticfeeding apparatus, the amount of material extruded from the dischargeport 65 may be controlled by adjusting a pressure acting on a liquidsurface of the material; and in the case that the feeding apparatus 200is a piston feeding apparatus, the amount of material extruded from thedischarge port 65 may be controlled in such a way that a drive apparatusadjusts a moving speed of a piston in a piston cylinder-shaped feedport.

That the amount of the material extrusion of the discharge port 65matches the length of the discharge port 65 means that t the amount ofthe material extrusion of the discharge port 65 changes in proportion tothe length of the discharge port 65.

During actual printing, the amount of the material extrusion may bedetermined according to the length of the discharge port 65. Then, theamount of material feeding of the feeding apparatus 200 may becontrolled so that the material feeding amount is equal to the amount ofthe material extrusion.

As shown in FIG. 4, the device 4 may also include a control apparatus 8for controlling the various drive apparatuses mentioned above. Thecontrol apparatus 8 may be a special-purpose numerical control device ora general-purpose processor. Furthermore, the control apparatus 8 may bea distributed control apparatus or a centralized control apparatus.

Hereinafter, description is made to a method embodiment of the presentapplication. Since the method embodiment may be performed by the device4 described above (specifically by the control apparatus 8 in the device4), parts not described in detail may refer to the above text.

FIG. 22 is a schematic flowchart of a control method provided by anembodiment of the present application. The control method of FIG. 22 maycontrol a device for 3D printing. The device may for example be thedevice 4 described above, and the control method may for example beperformed by the control apparatus 8 in the device 4.

The device may include a feeding pipe and a sleeve. An opening extendingalong an axial direction of the feeding pipe is disposed on an outerwall of the feeding pipe. A sleeve may be sleeved on the feeding pipe,and a discharge port in communication with the opening is disposed on anouter wall of the sleeve.

The method of FIG. 22 may include step S220 of adjusting a size of thedischarge port.

Optionally, the outer wall of the sleeve includes a first portion and asecond portion, and the first portion and the second portion areslidable relative to each other along the axial direction. Step S220 mayinclude: controlling the relative sliding between the first portion andthe second portion for adjusting the size of the discharge port.

Optionally, the first portion includes a first upper stepped surface, afirst lower stepped surface and a first connecting surface connectingthe first upper stepped surface and the first lower stepped surface, thesecond portion includes a second upper stepped surface, a second lowerstepped surface and a second connecting surface connecting the secondupper stepped surface and the second lower stepped surface, the firstupper stepped surface and the first lower stepped surface are in contactwith the second lower stepped surface and the second upper steppedsurface, respectively, and are slidable relative to the second lowerstepped surface and the second upper stepped surface along the axialdirection, and a hollow area formed by the first lower stepped surface,the first connecting surface, the second lower stepped surface and thesecond connecting surface is the discharge port.

Optionally, step S220 may include: adjusting the size of the dischargeport such that the length of the discharge port matches lengths ofintercept line segments of a cross-sectional contour line of a targetprinting region of a layer to be printed, where the target printingregion is part or all of a printing region of the layer to be printed.

Optionally, step S220 may include: adjusting the size of the dischargeport such that two ends for defining a length of the discharge port arealigned with the cross-sectional contour line of the target printingregion in a vertical direction.

Optionally, the method of FIG. 22 may further include: adjusting arelative position between the feeding pipe and the sleeve as a whole anda printing platform, such that two ends for defining the length of thedischarge port are aligned with the cross-sectional contour line of thetarget printing region in a vertical direction.

Optionally, the method of FIG. 22 may further include: determining allof the printing region of the layer to be printed as the target printingregion when a length of the longest intercept line segment of thecross-sectional contour line of the layer to be printed is less than orequal to the maximum length of the discharge port; or dividing all ofthe printing region of the layer to be printed into a plurality of thetarget printing regions when a length of the longest intercept linesegment of the cross-sectional contour line of the layer to be printedis greater than the maximum length of the discharge port.

Optionally, the method of FIG. 22 may further include: controlling afeeding apparatus to feed material for the discharge port such that theamount of the material extrusion of the discharge port matches the sizeof the discharge port.

Optionally, a plurality of discharge ports are disposed on the outerwall of the sleeve. The method of FIG. 22 may further include:controlling the sleeve to move relative to the feeding pipe such thatthe opening is capable of being in communication with differentdischarge ports.

Optionally, the plurality of the discharge ports are arranged along acircumferential direction of the sleeve, and the controlling the sleeveto move relative to the feeding pipe such that the opening is capable ofbeing in communication with different discharge ports may include:controlling the sleeve to be rotatable around an axis of the feedingpipe such that the opening is capable of being in communication withdifferent discharge ports.

Optionally, the widths of different discharge ports are different.

The above embodiments may completely or partly be implemented insoftware, hardware, firmware or a random combination thereof. Whenimplemented by software, they may completely or partly be implemented inthe form of a computer program product. The computer program productincludes one or more computer instructions. When the computer programinstructions are loaded and executed on a computer, the processes orfunctions described according to the embodiments of the presentapplication are completely or partly generated. The computer may be ageneral-purpose computer, a special-purpose computer, a computer networkor other programmable apparatus. The computer instructions may be storedin a computer-readable storage medium or transmitted from onecomputer-readable storage medium to another computer-readable storagemedium. For example, the computer instructions may be transmitted from aweb site, a computer, a server or a data center to another web site,computer, server or data center in a wired mode (for example, a coaxialcable, an optical fiber, a digital subscriber line (DSL)) or a wirelessmode (for example, infrared, radio, microwave or the like). Thecomputer-readable storage medium may be any available medium capable ofbeing accessed by a computer or a data storage device including aserver, a data center or the like integrated by one or more availablemedia. The available medium may be a magnetic medium (for example, asoft disk, a hard disk, a magnetic tape), an optical medium (forexample, a digital video disc (DVD)), or a semiconductor medium (forexample, a solid state disk (SSD)) or the like.

Those of ordinary skill in the art may be aware that, units andalgorithm steps of the examples described in the embodiments disclosedin the text can be implemented by electronic hardware, or a combinationof computer software and electronic hardware. Whether these functionsare performed by hardware or software depends on particular applicationsand designed constraint conditions of the technical solutions. Personsskilled in the art may use different methods to implement the describedfunctions for every particular application, but it should not beconsidered that such implementation goes beyond the scope of the presentapplication.

In the several embodiments provided in the present application, itshould be understood that, the disclosed system, apparatus and methodmay be implemented in other manners. For example, the describedapparatus embodiment is merely an example. For example, the unitdivision is merely logical function division and may be other divisionin actual implementation. For example, a plurality of units orcomponents may be combined or integrated into another system, or somefeatures may be ignored or not performed. In addition, the displayed ordiscussed mutual couplings or direct couplings or communicationconnections may be implemented by using some interfaces. The indirectcouplings or communication connections between the apparatuses or unitsmay be implemented in electrical, mechanical, or other forms.

The units described as separate components may or may not be physicallyseparate, and components displayed as units may or may not be physicalunits, may be located in one position, or may be distributed on multiplenetwork units. Some or all of the units may be selected according toactual requirements to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of this application maybe integrated into one processing unit, or each of the units may existalone physically, or two or more units are integrated into one unit.

The foregoing descriptions are merely specific embodiments of thepresent application, but the protection scope of the present applicationis not limited thereto, persons skilled in the art who are familiar withthe art could readily think of variations or substitutions within thetechnical scope disclosed by the present application, and thesevariations or substitutions shall fall within the protection scope ofthe present application. Therefore, the protection scope of the presentapplication shall be subject to the protection scope of the claims.

The invention claimed is:
 1. A device for 3D printing, comprising: afeeding pipe, wherein an opening extending along an axial direction ofthe feeding pipe is disposed on an outer wall of the feeding pipe; and asleeve sleeved on the feeding pipe, wherein a discharge port incommunication with the opening is disposed on an outer wall of thesleeve, wherein the outer wall of the sleeve comprises a first portionand a second portion, and the first portion and the second portion areslidable relative to each other along the axial direction forcontinuously adjusting the length of the discharge port, and wherein thefirst portion comprises a first upper stepped surface, a first lowerstepped surface and a first connecting surface connecting the firstupper stepped surface and the first lower stepped surface.
 2. The deviceaccording to claim 1, wherein the second portion comprises a secondupper stepped surface, a second lower stepped surface and a secondconnecting surface connecting the second upper stepped surface and thesecond lower stepped surface, the first upper stepped surface and thefirst lower stepped surface are in contact with the second lower steppedsurface and the second upper stepped surface respectively, the firstupper stepped surface is slidable relative to the second lower steppedsurface along the axial direction, the first lower stepped surface isslidable relative to the second upper stepped surface along the axialdirection, and a hollow area formed by the first lower stepped surface,the first connecting surface, the second lower stepped surface and thesecond connecting surface is the discharge port.
 3. The device accordingto claim 1, wherein the first portion is slidable relative to thefeeding pipe, and the second portion is fixedly connected to the feedingpipe or integrally formed with the feeding pipe.
 4. The device accordingto claim 3, wherein the first portion includes two ends defining alength of the first portion along the axial direction, and at least oneof the two ends of the first portion is a closed ring sleeved on thefeeding pipe.
 5. The device according to claim 1, wherein both the firstportion and the second portion are slidable relative to the feedingpipe.
 6. The device according to claim 5, wherein the first portionincludes two ends defining a length of the first portion along the axialdirection, and one of the two ends of the first portion is a closed ringsleeved on the feeding pipe; and/or the second portion includes two endsdefining a length of the second portion along the axial direction, andone of the two ends of the second portion is a closed ring sleeved onthe feeding pipe.
 7. The device according to claim 1, wherein the sizeof the discharge port is adjusted such that a length of the dischargeport matches lengths of intercept line segments of a cross-sectionalcontour line of a target printing region of a layer to be printed,wherein the target printing region is part or all of a printing regionof the layer to be printed.
 8. The device according to claim 7, whereinthe size of the discharge port is adjusted such that two ends fordefining the length of the discharge port are aligned with thecross-sectional contour line of the target printing region in a verticaldirection.
 9. The device according to claim 1, further comprising: afeeding apparatus configured to feed material for the discharge portthrough the feeding pipe; and a drive apparatus configured to drive thefeeding apparatus such that the amount of material extrusion of thedischarge port matches the size of the discharge port.
 10. The deviceaccording to claim 1, wherein a plurality of the discharge ports aredisposed on the outer wall of the sleeve, the widths of differentdischarge ports are different, the plurality of discharge ports arearranged along a circumferential direction of the sleeve, and the sleeveis rotatable around an axis of the feeding pipe such that the opening iscapable of being in communication with different discharge ports. 11.The device according to claim 1, wherein an interior of the feeding pipeis of an arc design.
 12. A control method of a device for 3D printing,wherein the device for 3D printing comprises: a feeding pipe, wherein anopening extending along an axial direction of the feeding pipe isdisposed on an outer wall of the feeding pipe; and a sleeve sleeved onthe feeding pipe, wherein a discharge port in communication with theopening is disposed on an outer wall of the sleeve; and the controlmethod comprises: adjusting a size of the discharge port, wherein theouter wall of the sleeve comprises a first portion and a second portion,and the first portion and the second portion are slidable relative toeach other along the axial direction, and the adjusting the size of thedischarge port comprises controlling the relative sliding between thefirst portion and the second portion for continuously adjusting the sizeof the discharge port, wherein the first portion comprises a first upperstepped surface, a first lower stepped surface and a first connectingsurface connecting the first upper stepped surface and the first lowerstepped surface.
 13. The control method according to claim 12, whereinthe second portion comprises a second upper stepped surface, a secondlower stepped surface and a second connecting surface connecting thesecond upper stepped surface and the second lower stepped surface, thefirst upper stepped surface and the first lower stepped surface are incontact with the second lower stepped surface and the second upperstepped surface respectively, the first upper stepped surface isslidable relative to the second lower stepped surface along the axialdirection, the first lower stepped surface is slidable relative to thesecond upper stepped surface along the axial direction, and a hollowarea formed by the first lower stepped surface, the first connectingsurface, the second lower stepped surface and the second connectingsurface is the discharge port.
 14. The control method according to claim12, wherein the adjusting the size of the discharge port comprises:adjusting the size of the discharge port such that a length of thedischarge port matches lengths of intercept line segments of across-sectional contour line of a target printing region of a layer tobe printed, wherein the target printing region is part or all of aprinting region of the layer to be printed.
 15. The control methodaccording to claim 14, wherein the adjusting the size of the dischargeport comprises: adjusting the size of the discharge port such that twoends for defining the length of the discharge port are aligned with thecross-sectional contour line of the target printing region in a verticaldirection.
 16. The control method according to claim 12, furthercomprising: controlling a feeding apparatus to feed material for thedischarge port such that the amount of material extrusion of thedischarge port matches the size of the discharge port.
 17. The controlmethod according to claim 12, wherein a plurality of the discharge portsare disposed on the outer wall of the sleeve, the plurality of thedischarge ports are arranged along a circumferential direction of thesleeve, and the control method further comprises: controlling therotation of the sleeve around an axis of the feeding pipe such that theopening is capable of being in communication with different dischargeports.
 18. The control method according to claim 17, wherein the widthsof different discharge ports are different.